Thermostatic control for steam-generators



C. FRIES AND H. W. FISHER.

THERMOSTAHC comnm FOR STEAM GENERATORS.

APPLICATION FILED SEPT-2,1919.

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THERMOSTAHC CONT-80L FOR STEAM GENERATORS.

APPLICATION FILED SEPT-2, 1919.

1,384,995. Patented July 19, 1921.

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04 i g m J *wk UNITED STATES PATENT OFFICE.

CHRIS FRIES, OF PERTH AMBOY, NEW JERSEY, AND HENRY W. FISHER, OF HUGUENOT PARK, NEW YORK.

Specification of Letters Patent.

Patented July 19, 1921.

Application filed September 2, 1919. Serial No. 320,986.

'70 all whom ii men concern:

Be it known t at we, CHRIS FRIES and HENRY W. FISHER, residing, respectively, at Perth Amboy, in the county of Middlesex and State of New Jerse and at Huguenot Park, in the county of ichmond and State of New York, respectively a subject of the King of Denmark and a citizen of the United States, have invented or discovered certain new and useful Improvements in Thermostatic Control for Steam-Generators, of which improvements the following is a specification.

Our invention relates to thermostatic control apparatus for steam generators. \Vhilc it may be used with steam generators for various specific purposes, it is particularly applicable to generators for steam propelled automobiles.

As now used, the power generator or plant of such automobiles includes a boiler of the fire-tube type to which water is supplied more or less continuously by a constantly acting pump. The amount of water flowing to the boiler is regulated by a valve thermostatically controlled by an element subjected to the heat of steam when the level of the water in the boiler falls below a predetermined minimum. It has been the cxperience of the users of such cars that, so long as the passage of the water supply conduits remain open and no leaks occur in such conduits or in the boiler, the power generators usually function properly. Occasionally, however, water conduit stoppages and leaks do occur, and if not immediately detected they may result, and in point of fact have resulted, disastrously, in the burning out of the boiler. For example, when certain of the water so ply conduits become clogged, the supply 0? water to the boiler may ail, with the result that the continuously burning fire burns out the boiler. Also, water from a leak in the water supply conduit may fall or be sprayed upon the superheated steam pipe or other portions of the thermostatic control apparatus explained above, with the result that such apparatus, being kept cool, will fail to respond to the conditions incident to the low water level in the boiler, and water will not be supplied to the boiler. This also may result in the burningout of the boiler. Finally, through a leak in the boiler, the water may flow from the boiler more rapidly than it is supplied, with the consequence just stated.

The object of our invention is to provide a simple and eflicient thermostatic control for steam generating apparatus, whereby the proper functioning of such apparatus may be assured under all conditions of service, as well as to protect the boiler from becoming burned out when emergencies arise.

Our invention is illustrated in the accompanying drawings in which Figure 1 isa vertical central sectional view ofasteam generating boiler combined with a diagrammatic representation of other apparatus, and Fig. 2 is a ,horizontal sectional view taken on the broken line II-II, Fig. 1, the valve structure being shown to enlarged scale.

In the practice of our invention we prol vide, between a steam generating boiler and the boiler-heating burner, a thermally expansible conduit having one end extendmg into the boiler and communicating with the interior of the boiler at the minimum desired water level. The conduit may be a pipe orany other suitable form of chambered member adapted to contain water received through its open end "from the boiler. From the boiler the conduit extends downwardly and substantially horizontally and is free to expand and contract according to the tem erature to which it is heated by the boiler burner. This expansion and contraction of the conduit is made effective to control the supply of liquid fuel, such as gas or oil, to the burner, or to control the supply of both water and fuel. When the water in the boiler is above the level of the open end of the conduit, such conduit is filled or partially filled with water from the boiler and is maintained substantially at the temperature of the boiler water. When, however, the boiler water level falls below the level of the open end of the conduit, the water in the conduit is soon converted into steam, and the conduit, becoming heated by the burner, expands, to cfl'ect the aforementioned control or controls of fluid supply to the apparatus. Thus a thermostatic control of the fluid supply is efiected directly by the heat of the burner, and the instrumentality for effecting the thermostatic control is itself utilized to heat the water in the boiler.

In the illustrative embodiment of our invention the steam generator consists of a boiler 1 mounted in a heat insulating jacket 2. and provided with vertical fines or fire tubes 3 for the passage of products of combustion. Below the boiler there is arranged an oil or gas burner 4,-although, as far as concerns some features of our invention, the boiler may be heated by burning solid fuel upon a grate 5. The supply of water to the boiler may be through a conduit (3, and the supply of fuel to the burner 4 may be through a conduit 7.

The means diagrammatically illustrated herein for supplying water to the boiler are such as are usually employed in steam propelled automobiles. A pump 8, continuously driven in a well known manner by an automobile engine, pumps water from a supply tank 9 into a conduit 10. which is divided to form the water supply conduit 6 leading to the boiler, and to form a by-pass conduit 11. The water-supply conduit 6 is provided with a check valve 12, which prevents steam from blowing backwardly into such conduit, but which becomes unseated to permit the flow of water into the boiler when the pressure applied to the water by thcspump exceeds the boiler steam pressure. uch pressure upon the water occurs when flow through the by-pass conduit 11 is stop ed by means of a thermostatically controlle valve 13 arranged in the by-pass conduit. The thermostat is here shown in the form of a tube 13 which O)QI1S to the boiler at the level desired for the water within. So long as said tube is submerged and flushed with water it is relatively cool and relatively contracted and valve 13 stands away from its seat; when the water in the boiler falls below the desired level and superheated steam gains access to tube 13*, the tube expands, valve 13 advances to its seat, and the bypass conduit 11 is closed.

To the casing 41 of the valve 13 there is attached a pipe 14 which extends to the inlet opening of a valve casing 15, to the outlet opening of which there is attached a pipe 16 which extends to the water tank. The flow of water through the by-pass pipes 14 and 16 is further controlled by a valve 17 (of Fig. 2) adapted to be moved by the thermally expansible conduit which we provide. \Vhile a single thermally expansible conduit may be employed. there are shown herein two such conduits 19 and 19. the ends of which project through the bottom of, and terminate at diti'ercnt levels within, the boiler 1. For convenience in the assembly and also in the removal of the conduits 18 and 19, (in case their removal becomes necessary for the purpose of cleaning them) each is attached to the bottom of the boiler by a tapered connection as indicated, and each is provided with a bend or turn extending outside of the heat insulating jacket 2. Both conduits 18 and 19 extend horizontally between the bottom of the boiler 1 and the burner 4, and both are subjected directly to the heat of such burner. The outer ends of the conduits 18 and 19 are connected to each other by means of apipe 20, provided intermediate of the conduits 18 and 19 with a valve 21, and provided at its outer ends with blow-off cocks 22 and 23. Union couplin 24 and 25 are preferably used for connecting the pipe"2() to the conduits 18 and 19.

By providing the valve 21 and the blowofl' cocks 22 and 23, the thermally expansible conduits may be either independently or simultaneously blown out. In case a stoppage should occur in one or the other of such conduits, access may be readily had thereto by uncou ling one or both of the unions 24 and 25. inally, if it becomes necessary to entirely remove one or the other of the expansible conduits for the purpose of repairing or cleaning it the provision of the tapered connection of the conduits to the boiler 1 facilitates such removal.

Both the conduits 18 and 19 extend freely through the insulation jacket 2 and are supported in such a manner that they are freely expansible longitudinally. As long as the water level in the boiler is above the upper J ends of the expansible conduits they wil the circulation of the boiler water throng them, be held at substantially the same temperature as that of the boiler water. When the level of the boiler water falls below the upper ends of the conduits the heat of the burner rapidly vaporizes the water remaining in them, and thereafter the conduits. becoming further heated by the burner. thermally expand in proportion to such heat'ng.

Various means may be employed for utilizing this expansion of the conduits 18 and 19, to the end that, first, water may be supplied to the boiler, and secondly, in case trouble should exist which prevents the supply of water to the boiler, the supply of fluid fuel may be shut off from the burner. In the illustrative embodiment of our invention there is removably and adjustably attached to the conduits 18 and 19 an arm 26 proided at its opposite ends with projections adapted, upon the expansion of the conduits, to first move the water controlling valve 17 and thereafter to move a gas controlling valve 27. The valve 17 is attached to a stem 28 provided with two fixed abutments or shoulders 29 and 30, and the arm 26 engages such stem ad'acent to the shoulder 29. a relatively sti spring 31 being arranged between the arm and the abutment 30. As will be seen from the arrows placed upon the pipes 14 and 16. the flow of water is such as normally to hold. the valve 17 open. When the conduits 18 and 19 expand the arm 26, acting upon the outer end of the ,permitting the arm 26 to move farther for the purpose of closing the valve 27.

The flow of fluid fuel, such as oil or gas,

I to the burners 4 is in a direction to normal] hold the valve 27 open, although, if desire a spring 32 may be arra ed upon the stem 33 of the valve 27 to he p urge the valve toward open position. After the arm 26 has closed the valve 17, its further movement in the same direction will, as just stated, close the valve 27, so that the supply of fuel will be completely shut off from the burner. Thus the boiler will not become burned out by reason of a failure of the water supply to it.

It will be understood that it is only under extraordinary circumstances that the supply of fuel will be shut off in the manner stated. That the operator may receive warning that conditions exist which are about to eflect a shutting off of the fuel supply, an electric bell 34 may, in the manner indicated in the drawings. be placed in a battery circuit which will be closed when an insulated con tactor 35 secured to the arm 26 strikes the end ofthe valve stem 33.

The advantage consequent upon the fact that conduits 18 and 19 open at different levels within boiler 1 is that, while the ends of both conduits continue to be immersed, a constant circulation of water through the conduits will be stimulated, in a direction from the conduit of lower level to that of higher level. In case the level of water within the boiler falls below that of the higher conduit, circulation will cease, but steam will. then be very quickly generated in the looped conduits and this steam, boiling through the water, will tend to clear the conduits of sediment. From experiment we know that water so contained in the 100 d tube, heated intensely by the burner isposed beneath, will shoot out with consider able force, freeing and expelling sediment. When the level falls below that of the lower conduit, all of the water segregated in the looped conduit will soon boil away and the thermostatic function will be performed, as already described.

In the operation of our invention as applied to steam generators for steam propelled automobiles, a thermostatically controlled valve 13 will usually be employed for controlling the flow of water to the boiler in the customarv manner in which such valve is now used. In case the thermostatic apparatus for controlling the valve 13 does not properly respond to the conditions incident to the requirement of further water for the boiler, and the water level in the boiler falls below the end of one or both of the conduits 18 and 19. such conduits will expand to effect a closing of the valve 17, so that water from the pum 8 will not be by-passed to the water tank 9, but will flow to the boiler. When conditions are such that, after the closing of the valve 17, the proper level of the water is not maintained, or in other words the water level does not rise above that of the ends of the conduits 18 and 19, these conduits will continue to expand, and by such expansion the valve 27 will be closed, the electric alarm 34 first being sounded. It will thus be seen that the expansible conduits 18 and 19, arranged in the manner contemplated herein, afford a safety device, whereby the liability of the burning out of the boiler is eliminated.

According to the provisions of the patent statutes, We have described the principle and operation of our invention together with a form of apparatus whereby it may be practised. However, we desire to have it understood that, within the scope of the appended claims, our invention may be practised by other forms of apparatus than that specificall shown and described.

\ e claim as our invention:

1. In steam generating apparatus, the combination of a boiler, a water tank, a conduit leading from tank to boiler, a by-pass leading from said conduit back to the tank again, a valve in said b -pass, a fluid-fuel burner beneath said bol er, a supply pipe leading to said burner, a valve in said fluid supply pipe, a conduit leading from said boiler above said burner, means whereby in response to thermal expansion of said conduit, the valve in said water by-pass and the valve ,in said fluid-fuel supply-pipe'are successively operated, and means for circulating water through the water system defined, substantially as described.

2. In steam-generating apparatus, the combination of a boiler, a water tank, a conduit leading from tank to boiler, a by-pass leading from said conduit back to said tank again, a valve in said by-pass, means f r maintaining a heating flame beneath said boiler, a looped conduit leading from said ,boiler through the region of flame and back to the boiler again at another level than the point whence the conduit leads, operative connection be ween said looped conduit and said valve in t e by-pass, and means for circulating water through the system, substantially as described.

3. In steam-generating apparatus, the combination of a boiler, a water tank, a conduit leading from tank to boiler, means for heating the? boiler, a by-pass leading from said conduit back ,to said tank again, means for maintaining circulation of water through the system defined, means for closing circulation through said by-pass and opening it again, 'accordin as the level of water within the boiler alls below or rises above the desired point, and emergency means for preventing the boiler from running dry and being then burnt out, operative in case the means last defined fail to function, such emergency means including a conduit leading from said boiler at a point adjacent its bottom and extending into the region of boiler heating, such conduit by thermostatic expansion and contraction controlling circulation of water through said by-pass, substantially as described.

In testimony whereof we have hereunto set our hands.

CHRIS FRIES. HENRY W. FISHER.

Witnesses:

TRACY D. WAEING, BRUCE E. DOLCH. 

